<html>
<head>  
  <title>网页标题</title>
  <style type="text/css">
    .mybody{
      width:500px;
      height:450px;
      margin:50px;
      background-color:#ff0;
    }
    .p1{
      width:250px;
      height:250px;
      background-color:black;
      position:absolute;
      left:10px;
      top:10px;
      z-index:8;
    }
    .p2{
      width:200px;
      height:200px;
      background-color:#2f0;
      position:absolute;
      left:10px;
      top:10px;
      z-index:9;
    }
  </style>
</head>
<body>
  <div class="mybody">
	  <div class="p1"></div>
	  <div class="p2"></div>
  </div>
</body>
</html>
